I liked all of those pistols fine but being the 10mm Auto is my favorite handgun cartridge I am throughly grateful to see Coonan adding that cartridge to their growing line of handguns.

First Impressions

Notice the extended thumb safety and slide stop. The pivoting trigger broke clean at 3 1/2 pounds with just a touch of take up and minimum over travel.

Note the spring loaded external extractor, skeletonized speed hammer.

Beavertail grip safety with incorporated palm swell. You have the option on the steel mainspring housing for checkering.

Rear 2 dot sight is adjustable for windage via set screw and drift adjusting in the dovetail. Coonan offers several options for sight configurations. Slide to receiver fit was snug but not tight enough to cause any issues.

The front sight is dovetailed and nicely blended into the muzzle of the slide.

Average 3 shot group shot from a rest at 25 yards. Please see the chart for complete list of ammunition and groups shot.

After some 300 rounds all the innards checked out with no signs of wear. I know 300 rounds is not an awful lot of rounds downrange but if something was not fit correctly or there was a problem, I expect it would have shown up by now.

3 shot 25 yard groups from a rest

Range Time

Conclusions

After some 300 rounds downrange without any issues with the pistol, I am digging the new Coonan 10mm. I would see this pistol serving very well as a carry gun for street or trail as well as home defense. The 10mm Auto is a powerful cartridge, exceeding the single stack .45 Auto in energy and capacity and .357 Magnum energies with the benefit of being chambered in an autoloader. The Coonan is a cross between a 1911 and a Browning Hi-Power which brings a few unique features, such as the linkless barrel, to bear that is conducive to running a high pressure round while keeping wear and tear to a minimum. Even with the monolith cut on the dust cover the Coonan fit the leather 1911 holsters I had on hand. Personally I favor the new optional satin finish over the stainless, and am hoping Coonan will decide to offer it as an option on other pistols. All in all I am satisfied with Coonan’s new offering and I look forward to it being released into the wild.

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About Hunter Elliott

I spent much of my youth involved with firearms and felt the call early on to the United States Marine Corps, following in my father's and his brother's footsteps. Just after high school I enlisted and felt most at home on the rifle range, where I qualified expert with several firearms and spent some time as a rifle coach to my fellow Marines. After being honorably discharged I continued teaching firearm safety, rifle and pistol marksmanship, and began teaching metallic cartridge reloading. In the late 1990s I became a life member to the National Rifle Association and worked with the Friends of the NRA. Around that time my father and I became involved with IDPA and competed together up until he passed away. I began reviewing firearms for publications in the mid 2000s and have been fortunate to make many friends in the industry. Continuing to improve my firearms skills and knowledge is a never ending journey in which we should all be committed. I am also credited as weapons master on a few independent films.

15 Responses to Coonan 10mm Automatic, life imitating art

Where do you get this “The 10mm Auto is a powerful cartridge, exceeding………….. .357 Magnum energies”? Following the link in this article to Double Tap’s website and looking to make as much of an “apples to apples comparison” as possible. I found that their 10mm loads with 155gr bullets have a muzzle velocity of 1400 fps and develop 675ft/lbs of muzzle energy out of a Glock 20. Their 158gr .357 Magnum loads have a muzzle velocity of 1400 fps and develop 688ft/lbs of muzzle energy out of a 4″ Ruger GP-100. The .357 has a slight edge but for practical purposes they develop the same energy. Which of the two “develops more energy” depends upon the specific loads compared rather than the cartridge. The real issue in choosing between the two cartridges is the type of gun. 10mm works better in semi-autos and .357Magnum works better in revolvers.

Yes but ft lbs of energy is not the end all be all number. The 10mm Auto can be loaded up to a 220gr bullet while the heaviest .357 Magnum is 158gr. Also the 10mm Auto is launching a .40″ bullet over the .357 bullet. So you have a larger, and heavier bullet that can be loaded to similar velocities.
The 10mm Auto is a more powerful cartridge when every aspect is considered.

Well you did specify “exceeding………….. .357 Magnum energies”. So I focused on energy levels. Still the.357 Magnum can be loaded with bullets exceeding 158 gr. Underwood and, Buffalo Bore for example each list loads with 180gr bullets and Cor Bon has a load with a 200 gr bullet. And the cartridge can be handloaded with even heavier bullets. See http://www.handloads.com/loaddata/default.asp?Caliber=357%20Magnum&Weight=All&type=Handgun. So you can go heavier with bullets for the .357. That does not always translate into higher “energies”as velocity usually goes down with a heavier bullet.The 10mm does have a larger diameter bullet which helps on the Taylor KO Factor.But the difference in bullet diameter is not that great.The exact diameter of a .357 bullet is 9.07mm vs 10.16 for the 10mm. Again I would maintain that the two rounds are basically equal.

I have done my homework, you can load up to a 220gr in the 10mm Auto.
Even with the 180gr the .357 Magnum and 10mm Auto have similar velocities, but the 180gr is a non typical bullet weight for the .357. The heavy 10mm Auto loads tread into .41 Magnum energies.

Let’s take a look at this comparison. Buffalo Bore loads both a 10mm with a 220gr bullet and a .357 Magnum with a 180gr bullet..Their 10mm 220 gr load has a muzzle velocity of 1200 fps and produces 703 Foot Pounds of muzzle energy. Their 180gr .357Magnum load has a muzzle velocity of 1400 fps and produces 783 Foot Pounds of muzzle energy. Buffalo Bore is not known for wimpy ammo so it is safe to say you are not likely to find much hotter factory ammo than this. Remember the .357Magnum has more case capacity than does the 10mm although the 10mm has a higher maximum pressure.he two factors pretty much balance themselves out when it comes to power potential of the two cartridges.. .

i know every time i pop a few rounds through the 1911 .357 magnum i WISH i could be dealing with a cylinder gap!

having carried numerous .357 mag revolvers on my belt since the late 70s, i would never go back to one, unless i’m dinkin around at the range (or out huntin wabbits). the 1911 is a superior platform for defense when compared to a wheel gun.

I have owned a Coonan 1911 357 mag. Model B since 1989 and I love the way it shoots. It goes to the range with me 95% of the time. I also shoot 1911’s in 45, 38 super and 9mm and it looks like a 1911 in 10mm is going to be my next buy.

If you really want to compare the .357 to the 10mm you have to do so as equally as possible. Now, how can you compare the 10mm Coonan to a .357? Wait, how about compare it to the Coonan Classic in… wait for it… .357. The other thing to note is that every single official statistic on the .357 cartridge is in what type of firearm? That’s right, a revolver. Can anyone figure out what the lack of a cylinder gap in the Coonan will do to the actual performance of the .357? Last I heard, and read, was increase it. Into… wait for it… .41 mag energies. And 180gr is no longer an atypical .357 load. I run 180gr Remingtons, Armsacor and a few others through my Classic.

HI thanks for your feed back ,I am a ex South African and have hunted with the .357 mag for the last 25 year,s and have seen animals drop real hard with a .357 mag ,have also been reloading for a good 42 years and it has always been my to go Rifle for most of you med size game ,I have seen the .357 mag go through a lot of things with that 180 gr bullet ,I am a Rifle builder here in the USA now ,I will be getting a Coonan .357 mag very soon did see them at the Shot Show this year and at the NRA here in Atlanta ,have sighed up to be a dealer for this year ,but the $$$$ is going very slow.
Thanks Bernard

Hi Hunter
Always enjoy your reviews. After owning a New Generation Delta Elite, a Dan Wesson Bruin, a Glock 20, and a Glock 40 MOS, I’m going to make a statement that might piss off some people. Right now I feel the Glock 40 is the best 10mm platform on the market, here’s why.
The 1911 design (I love the 1911, own an Ed Brown Alpha Carry) does not hold up well to a constant diet of full house, think a Underwood, ammo. I talked to Ed Btown about building me a 5” 10mm and they said 6” only for Pistol longevity. I think the Brown Family knows a thing or to about 1911’s. The lock up on a 1911, barrel lug, barrel link in particular take a battering from full house 10mm. I noticed some very slight peening of the lugs on my DE after only 400rds of Underwood. That why I sold it and bought the Dan Wesson Bruin. I think the added slide mass and better springing reduces the battering. The Bruin shows no signs of battering after 600rds of Underwood. But a 5” 1911 that’s a beating from full house 10mm. I’ve talked to people who own DE Razor Backs, Silver Backs, Sig TACOPS, RIA, and Other Colt DE owners. All the ones that said they fired hot 10mm ammo on a regular basis, I asked to closely inspect the lugs, link, slide stop frame area, and bushing. All but a couple said they noticed the slight wearing. So for the occasional range session or only carrying the hot 10mm ammo I think a 5” 1911 is okay. I owned a Coonan Model B .357mag for 4 years. I’m not a fan of cast frames and slides, and I believe the Coonan’s are still cast pistols? Also how many and what internals are MIM?

Why the Glock 40 is better.The Glocks polymer frame flex’s slightly which reduces battering along with the increased mass of the 6” slide. Its lock up is better to not batter the pistol. It’s wider back strap spreads out the recoil. It’s the softest shoot 10mm I’ve ever fired. It’s lighter weight gives you 16rds at the empty weight of the 10mm 1911’s. Yeah it’s a Glock, with the Glock Trigger but it’s not really that bad and I’ve become extremely proficient with this pistol. Mine is bone stock and I’ve fired over 700rds of very hot 10mm, as well as over 1,000rds of 180gr FMJ S&B . The S&B ammo is $12.99-$13.99 per 50 and chrono’s Just at 1190 from the 6” barrel, not bad for plinking. The pistol shows no signs of wear. The brass all looks perfect, no smiles or bulges, and the pistol is very accurate!. Let the haters hate.

Grant.
That is a very well put together comment. Everything thing you said is true and I agree. The only thing we differ on is I prefer the Bruin to the Glock 40.
I appreciate your thoughts on this. I don’t think anyone can argue with your comment that understands the two platforms and approaches it with logic and no emotion.